The present invention relates to a fluid coupler comprising male and female coupler members, and more particularly to a fluid coupler adapted to be automatically disassembled or uncoupled in an emergency or in a case where an excessive tension is applied to a fluid line in which the coupler is installed or connected in order to prevent the fluid line from being damaged by the excessive tension.
A representative coupler of this type comprises male and female coupler members each having a spring-biased valve for opening and closing the fluid passage thereof. In use, the male and female coupler members are fixedly connected to each other by a spring-biased connection means with the valves of the male and female coupler members being opened to establish fluid communication between the fluid passages of the male and female coupler members.
When an excessive tension is accidentally applied to a fluid line having the fluid coupler installed therein, the spring biased connection device is disenabled or adversely affected by the excessive tension, whereby the male and female coupler members are disconnected from each other.
This type of coupler involves the following problems: When an excessive tension is applied to the fluid line, the fixed connection between the male and female coupler members established by the spring-biased connection device is cancelled or broken and, simultaneously, the valves of the male and female coupler members are closed. Accordingly, pressurized fluid remains in the fluid passage between the closed valves of the male and female coupler members which have not yet been separated from each other, even though the fixed connection therebetween has been cancelled or broken. The pressurized fluid therefore acts on the male and female coupler members and may abruptly and violently separate them, whereby the separated male coupler member and/or female coupler member may collide against and cause damage to any objects in the area surrounding the coupler, and as a result, become damaged.
Further, since coupler members of a conventional fluid coupler of this type are designed so that they can be connected with each other by simply inserting the male coupler member into the female coupler member after the above-stated separation, the coupler members may be connected and used again in spite of the damage thereto.
Accordingly, it is an object of the present invention to provide a fluid coupler having structure for preventing male and female coupler members from being abruptly and violently separated from each other by pressure of fluid remaining between valves of the male and female coupler members, which have been closed in response to cancellation of or a break in a fixed connection between the male and female coupler members.
Another object of the present invention is to provide a fluid coupler in which the male and female coupler members are prevented from being coupled by simply inserting the male coupler member into the female coupler member after they are separated from each other by an excessive tension applied to the fluid line in which the fluid coupler is connected.
According to the present invention, there is provided a fluid coupler comprising:
a female coupler member having a first fluid passage and a male coupler member receiving hole having an axis; and,
a male coupler member having a second fluid passage, the male coupler member being inserted into the male coupler member receiving hole along the axis of the male coupler member receiving hole so that the male coupler member is brought into a fixed connection condition in which the male coupler member is fixedly connected to the female coupler member and retained at a fixed connection position relative to the female coupler member, with the fixed connection condition being cancelled or broken when an excessive tension is applied to a fluid line in which the fluid coupler member is installed such that tension acts on the male and female coupler members to separate them.
The female coupler member has an interior surface extending in parallel with the axis and defining the male coupler member receiving hole, and the first fluid passage of the female coupler member has an end opening at the interior surface.
The male coupler member has an exterior surface extending in parallel with the axis of the male coupler member receiving hole, and the second fluid passage of the male coupler member has an end opening at the exterior surface of the male coupler member.
The coupler further comprises a first valve movably connected to one of the male and female coupler members and positioned between the exterior surface of the male coupler member inserted into the male coupler member receiving hole, and the interior surface of the female coupler member. The first valve has an outer surface and an inner surface to be slidably engaged with the interior surface and the exterior surface mentioned above, respectively, and, a through hole having an outer end opening at the outer surface and an inner end opening at the inner surface. Under the fixed connection condition, the outer and inner ends of the through hole are aligned with the one end of the first fluid passage and the one end of the second fluid passage, respectively, to effect fluid communication between the first and second fluid passages. Fluid communication between the first and second fluid passages via the through hole is cancelled due to loss of the alignment of the ends of the though hole with respect to at least one of the above-mentioned one ends of the first and second fluid passages, which is caused when the male coupler member is moved in a direction opposite to a direction of insertion of the male coupler member into the female coupler member after cancellation of the fixed connection condition.